fix: Add OIDC notice to NIC Custom OIDC Docs

[AlexFenlon]

Proposed changes

Add a notice to custom OIDC doc in NIC that it only works in previous versions.

Checklist

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• I read the Contributing guidelines
• My branch adheres to the Git conventions
• My content changes adhere to the F5 NGINX Documentation style guide
• If my changes involve potentially sensitive information¹, I have assessed the possible impact
• I have waited to ensure my changes pass tests, and addressed any discovered issues

Footnotes

1. Potentially sensitive information includes personally identify information (PII), authentication credentials, and live URLs. Refer to the style guide for guidance about placeholder content. ↩

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[ADubhlaoich]

LGTM, though it could probably be rephrased.

I assume this use case has been "deprecated" due to the native NGINX OIDC module.

I would change the notice to say something along the lines of:

"This guide is only necessary for NGINX Ingress Controller versions x or earlier. To use OIDC with newer NGINX Ingress Controller versions, please view the XYZ topic".